For example, in a tire running test apparatus for a tire as disclosed in PTL 1, a belt looped between a pair of drums may be meandering or shifted from a proper position during the test of a tire. Hence, in this tire running test apparatus, the position of the belt is actually measured and then the swing quantity of the drum is made variable, to control the position of the belt.
A control system represented by this tire running test apparatus has dynamic characteristics having dead time and integration characteristics, and therefore may be conceived as “an astatic system having dead time.”
As a control method of compensation for such “an astatic system having dead time,” Smith compensation is well known.
For example, PTL 2 discloses a dead time compensation control unit that compensates for dead time at a control unit that feeds back the output of a control target having dead time and executes PI control or PID control based on the deviation from a target value. This dead time compensation control unit compensates for the dead time at the control target with a Smith compensator by a dead time Smith compensation method, and compensates for the dead time in the control unit with a control unit dead time compensator including control unit model means and control unit dead time model means.